Finishing touches on wording adjustments

Author: w-azure

articles/iot-hub/iot-hub-csharp-csharp-c2d.md

@@ -16,41 +16,40 @@ ms.custom:  [amqp, mqtt, 'Role: Cloud Development', 'Role: IoT Device', devx-tra
 
 [!INCLUDE [iot-hub-selector-c2d](../../includes/iot-hub-selector-c2d.md)]
 
-Azure IoT Hub is a fully managed service that helps enable reliable and secure bi-directional communications between millions of devices and a solution back end. The [Send telemetry from a device to an IoT hub](../iot-develop/quickstart-send-telemetry-iot-hub.md?pivots=programming-language-csharp) quickstart shows how to create an IoT hub, provision a device identity in it, and code a device app that sends device-to-cloud messages.
+Azure IoT Hub is a fully managed service that helps enable reliable and secure bi-directional communications between millions of devices and a solution back end. 
 
-[!INCLUDE [iot-hub-basic](../../includes/iot-hub-basic-whole.md)]
-
-This article builds on [Send telemetry from a device to an IoT hub](../iot-develop/quickstart-send-telemetry-iot-hub.md?pivots=programming-language-csharp). It shows you how to do the following tasks:
+This article shows you how to:
 
-* From your solution back end, send cloud-to-device messages to a single device through IoT Hub.
+* Send cloud-to-device messages, from your solution backend, to a single device through IoT Hub
 
-* Receive cloud-to-device messages on a device.
+* Receive cloud-to-device messages on a device
 
-* From your solution back end, request delivery acknowledgment (*feedback*) for messages sent to a device from IoT Hub.
+* Request delivery acknowledgment (*feedback*), from your solution backend, for messages sent to a device from IoT Hub
 
-You can find more information on cloud-to-device messages in [D2C and C2D Messaging with IoT Hub](iot-hub-devguide-messaging.md).
+[!INCLUDE [iot-hub-basic](../../includes/iot-hub-basic-whole.md)]
 
 At the end of this article, you run two .NET console apps.
 
-* **SimulatedDevice**. This app connects to your IoT hub and receives cloud-to-device messages. This app is a modified version of the app created in [Send telemetry from a device to an IoT hub](../iot-develop/quickstart-send-telemetry-iot-hub.md?pivots=programming-language-csharp).
+* **SimulatedDevice**: a modified version of the app created in [Send telemetry from a device to an IoT hub](../iot-develop/quickstart-send-telemetry-iot-hub.md?pivots=programming-language-csharp), which connects to your IoT hub and receives cloud-to-device messages.
 
-* **SendCloudToDevice**. This app sends a cloud-to-device message to the device app through IoT Hub, and then receives its delivery acknowledgment.
+* **SendCloudToDevice**: sends a cloud-to-device message to the device app through IoT Hub and then receives its delivery acknowledgment.
 
 > [!NOTE]
-> IoT Hub has SDK support for many device platforms and languages, including C, Java, Python, and JavaScript, through [Azure IoT device SDKs](iot-hub-devguide-sdks.md). For step-by-step instructions on how to connect your device to this article's code, and generally to Azure IoT Hub, see the [IoT Hub developer guide](iot-hub-devguide.md).
->
+> IoT Hub has SDK support for many device platforms and languages (C, Java, Python, and JavaScript) through [Azure IoT device SDKs](iot-hub-devguide-sdks.md).
+
+You can find more information on cloud-to-device messages in [D2C and C2D Messaging with IoT Hub](iot-hub-devguide-messaging.md).
 
 ## Prerequisites
 
 * Visual Studio
 
-* An active Azure account. If you don't have an account, you can create a [free account](https://azure.microsoft.com/pricing/free-trial/) in just a couple of minutes.
+* A complete working version of the [Send telemetry from a device to an IoT hub](../iot-develop/quickstart-send-telemetry-iot-hub.md?pivots=programming-language-java) quickstart or the [Configure message routing with IoT Hub](tutorial-routing.md) article. This cloud-to-device article builds on the quickstart.
 
 * Make sure that port 8883 is open in your firewall. The device sample in this article uses MQTT protocol, which communicates over port 8883. This port may be blocked in some corporate and educational network environments. For more information and ways to work around this issue, see [Connecting to IoT Hub (MQTT)](iot-hub-mqtt-support.md#connecting-to-iot-hub).
 
 ## Receive messages in the device app
 
-In this section, modify the device app you created in [Send telemetry from a device to an IoT hub](../iot-develop/quickstart-send-telemetry-iot-hub.md?pivots=programming-language-csharp) to receive cloud-to-device messages from the IoT hub.
+In this section, modify your device app to receive cloud-to-device messages from the IoT hub.
 
 1. In Visual Studio, in the **SimulatedDevice** project, add the following method to the **SimulatedDevice** class.
 
@@ -90,27 +89,26 @@ With AMQP and HTTPS, but not MQTT, the device can also:
 
 If something happens that prevents the device from completing, abandoning, or rejecting the message, IoT Hub will, after a fixed timeout period, queue the message for delivery again. For this reason, the message processing logic in the device app must be *idempotent*, so that receiving the same message multiple times produces the same result.
 
-For more detailed information about how IoT Hub processes cloud-to-device messages, including details of the cloud-to-device message lifecycle, see [Send cloud-to-device messages from an IoT hub](iot-hub-devguide-messages-c2d.md).
+For more information about the cloud-to-device message lifecycle and how IoT Hub processes cloud-to-device messages, see [Send cloud-to-device messages from an IoT hub](iot-hub-devguide-messages-c2d.md).
 
 > [!NOTE]
 > When using HTTPS instead of MQTT or AMQP as a transport, the `ReceiveAsync` method returns immediately. The supported pattern for cloud-to-device messages with HTTPS is intermittently connected devices that check for messages infrequently (a minimum of every 25 minutes). Issuing more HTTPS receives results in IoT Hub throttling the requests. For more information about the differences between MQTT, AMQP, and HTTPS support, see [Cloud-to-device communications guidance](iot-hub-devguide-c2d-guidance.md) and [Choose a communication protocol](iot-hub-devguide-protocols.md).
->
 
 ## Get the IoT hub connection string
 
-In this article, you create a back-end service to send cloud-to-device messages through the IoT hub you created in [Send telemetry from a device to an IoT hub](../iot-develop/quickstart-send-telemetry-iot-hub.md?pivots=programming-language-csharp). To send cloud-to-device messages, your service needs the **service connect** permission. By default, every IoT Hub is created with a shared access policy named **service** that grants this permission.
+In this article, you create a back-end service to send cloud-to-device messages through your IoT Hub. To send cloud-to-device messages, your service needs the **service connect** permission. By default, every IoT Hub is created with a shared access policy named **service** that grants this permission.
 
 [!INCLUDE [iot-hub-include-find-service-connection-string](../../includes/iot-hub-include-find-service-connection-string.md)]
 
 ## Send a cloud-to-device message
 
-In this section, you create a .NET console app that sends cloud-to-device messages to the simulated device app.
+In this section, you create a .NET console app that sends cloud-to-device messages to the simulated device app. You need the device ID from your device and your IoT hub connection string.
 
-1. In the current Visual Studio solution, select **File** > **New** > **Project**. In **Create a new project**, select **Console App (.NET Framework)**, and then select **Next**.
+1. In Visual Studio, select **File** > **New** > **Project**. In **Create a new project**, select **Console App (.NET Framework)**, and then select **Next**.
 
 1. Name the project *SendCloudToDevice*, then select **Next**.
 
-   ![Configure a new project in Visual Studio](./media/iot-hub-csharp-csharp-c2d/sendcloudtodevice-project-configure.png)
+   :::image type="content" source="./media/iot-hub-csharp-csharp-c2d/sendcloudtodevice-project-configure.png" alt-text="Screenshot of the 'Configure a new project' popup in Visual Studio." lightbox="./media/iot-hub-csharp-csharp-c2d/sendcloudtodevice-project-configure.png":::
 
 1. Accept the most recent version of the .NET Framework. Select **Create** to create the project.
 
@@ -167,7 +165,7 @@ In this section, you create a .NET console app that sends cloud-to-device messag
 
 ## Receive delivery feedback
 
-It is possible to request delivery (or expiration) acknowledgments from IoT Hub for each cloud-to-device message. This option enables the solution back end to easily inform retry or compensation logic. For more information about cloud-to-device feedback, see [D2C and C2D Messaging with IoT Hub](iot-hub-devguide-messaging.md).
+It's possible to request delivery (or expiration) acknowledgments from IoT Hub for each cloud-to-device message. This option enables the solution back end to easily inform, retry, or compensation logic. For more information about cloud-to-device feedback, see [D2C and C2D Messaging with IoT Hub](iot-hub-devguide-messaging.md).
 
 In this section, you modify the **SendCloudToDevice** app to request feedback, and receive it from the IoT hub.
 
@@ -218,6 +216,6 @@ In this section, you modify the **SendCloudToDevice** app to request feedback, a
 
 ## Next steps
 
-In this how-to, you learned how to send and receive cloud-to-device messages.
+In this article, you learned how to send and receive cloud-to-device messages.
 
 To learn more about developing solutions with IoT Hub, see the [IoT Hub developer guide](iot-hub-devguide.md).

articles/iot-hub/iot-hub-ios-swift-c2d.md

@@ -14,24 +14,22 @@ ms.custom: mqtt
 
 [!INCLUDE [iot-hub-selector-c2d](../../includes/iot-hub-selector-c2d.md)]
 
-Azure IoT Hub is a fully managed service that helps enable reliable and secure bi-directional communications between millions of devices and a solution back end. The [Send telemetry from a device to an IoT hub](../iot-develop/quickstart-send-telemetry-iot-hub.md) quickstart shows how to create an IoT hub, provision a device identity in it, and code a simulated device app that sends device-to-cloud messages.
+Azure IoT Hub is a fully managed service that helps enable reliable and secure bi-directional communications between millions of devices and a solution back end. 
 
 This article shows you how to:
 
-* Receive cloud-to-device messages on a device.
-
-You can find more information on cloud-to-device messages in the [messaging section of the IoT Hub developer guide](iot-hub-devguide-messaging.md).
+* Receive cloud-to-device messages on a device
 
 At the end of this article, you run the following Swift iOS project:
 
-* **sample-device**, the same app created in [Send telemetry from a device to an IoT hub](../iot-develop/quickstart-send-telemetry-iot-hub.md), which connects to your IoT hub and receives cloud-to-device messages.
+* **sample-device**: the same app created in [Send telemetry from a device to an IoT hub](../iot-develop/quickstart-send-telemetry-iot-hub.md), which connects to your IoT hub and receives cloud-to-device messages.
 
 > [!NOTE]
-> IoT Hub has SDK support for many device platforms and languages (including C, Java, Python, and JavaScript) through Azure IoT device SDKs. For step-by-step instructions on how to connect your device to this article's code, and generally to Azure IoT Hub, see the [Azure IoT Developer Center](https://www.azure.com/develop/iot).
+> IoT Hub has SDK support for many device platforms and languages (including C, Java, Python, and JavaScript) through the [Azure IoT device SDKs](iot-hub-devguide-sdks.md).
 
-## Prerequisites
+You can find more information on cloud-to-device messages in the [messaging section of the IoT Hub developer guide](iot-hub-devguide-messaging.md).
 
-* An active Azure account. (If you don't have an account, you can create a [free account](https://azure.microsoft.com/pricing/free-trial/) in just a couple of minutes.)
+## Prerequisites
 
 * An active IoT hub in Azure.